Tuesday, 29 March 2022

Musivavis amabilis: A new species of Enantiornithine Bird from the Early Cretaceous Jehol Biota of northeastern China.

The Enantiornithines are the most diverse group of Cretaceous Birds known, with more than 50 described species from every continent except Antarctica. Although they were clearly widespread, more than half of all known Enantiornithines come from the Jehol Biota of northeastern China. The Jehol fossils are exceptionally well preserved, with many showing  details of their plumage and internal organs, which has provided insights into these Birds ontogeny, sexual dimorphism, reproduction, and ecology. Most Enantiornithine Birds can be placed within four groups, the small-bodied and relatively unspecialized Cathayornithids, the long-snouted Longipterygids, and the large-bodied Bohaiornithids and Pengornithids, although there is some dispute as to whether these represent true clades (groups of organisms derived from a single common ancestor, or evolutionary grades (groups of organisms with the same level of organisation, but which do not share common ancestries).

In a paper published in the Journal of Paleontology on 11 March 2022, Xuri Wang of the Key Laboratory of Stratigraphy and Paleontology of the Ministry of Natural Resources at the Institute of Geology of the Chinese Academy of Geological Sciences, and the Hebei GEO University, Andrea Cau of Parma in Italy, Xiaoling Luo of the Research Center of Development of the China Geological Survey, Martin Kundrát of the Center for Interdisciplinary Biosciences at the University of Pavol Jozef Šafárik, Wensheng Wu, also of the Hebei GEO University, Shubin Ju, also of the Key Laboratory of Stratigraphy and Paleontology of the Ministry of Natural Resources and of the China University of Geosciences, Zhen Guo, again of the Hebei GEO University, Yichuan Liu, again of the Key Laboratory of Stratigraphy and Paleontology of the Ministry of Natural Resources and the China University of Geosciences, and Qiang Ji, once again of the Hebei GEO University, describe a new species of Enantiornithine Bird from the Jehol Biota. 

The new species is named Musivavis amabilis, where 'Musivavis' means 'Mosaic Bird' in reference to the range of features seen in the specimen, which show affinities to more than one Enantiornithine group, and 'amabilis' means 'attractive' in Latin, in reference to the beautiful preservation of the single specimen from which the species is described. The species is described from a single specimen, MHGU-3000, a nearly complete and articulated skeleton preserved in a single slab, which was excavated at the Shangheshou locality in Chaoyang City in Liaoning Province.

Holotype (MHGU-3000) of Musivavis amabilis from the Early Cretaceous Jiufotang Formation (Aptian). (1) photograph; (2) line drawing. Abbreviations: al, alular metacarpal; ald, alular digits; an, angular; cav, caudal vertebrae; cv, cervical vertebrae; d, dentary; fu, furcula; fr, frontal; hy, hyoid; il, ilium; lco, left coracoid; lfe, left femur; lfi, left fibula; lh, left humerus; lr, left radius; lsc, left scapula; lti, left tibiotarsus; ltm, left tarsometatarsus; lu, left ulna; m, maxilla; m-Ⅰ–Ⅳ, metatarsal Ⅰ-Ⅳ; mac, major metacarpal; mad, major manual digits; mic, minor metacarpal; mid, minor manual digits; n, nasal; pa, parietal; pd-Ⅰ–Ⅳ, pedal digitⅠ-Ⅳ; pr, premaxilla; pu, pubis; py, pygostyle; rco, right coracoid; rfe, right femur; rfi, right fibula; rh, right humerus; rl, radiale; rr, right radius; rsc, right scapula; rti, right tibiotarsus; ru, right ulna; se, semilunate carpal; sr, scleral ring; st, sternum; su, surangular; syn, synsacrum; ul, ulnare. Wang et al. (2022).

Musivavis amabilis possesses a number of features associated with the Bohaiornithidae, including subconical teeth with tapered and slightly caudally recurved tips, a sternum with lateral trabecula projected caudolaterally, a blunt expansion of the omal end of the furcular ramus, and a tapering pygostyle without an abrupt distal constriction. 

The skull is mainly preserved in ventrolateral view. The right premaxilla is preserved in lateral view. It gradually tapers rostrally and slightly expands dorsoventrally in the middle part, differing from the robust premaxilla of the Bohaiornithids, and the elongated premaxilla of the Longipterygids, but similar in overall proportions to those of the Cathayornithidae. The frontal process of the right premaxilla is elongate and projects caudodorsally, but does not extend to the orbit, comparable with the condition in Bohaiornithids. As in other Bohaiornithid-like taxa, the maxilla is robust, with a straight ventral margin and gently expanded dorsal margin. The nasal is too broken to determine the exact anatomical features. The right lacrimal is preserved in dorsolateral view and appears to be 'T'-shaped. The rostral ramus is oriented rostroventrally, but the exact length cannot be determined because it is overlapped by the right maxilla. The caudal ramus projects caudodorsally and the ventral ramus extends caudoventrally. The dorsal margin is concave at the middle part.

Skull of the holotype (MHGU-3000) of Musivavis amabilis in ventrolateral view. (1) photograph; (2) line drawing; (3) close-up of the rostral portion; (4) micro-CT scan of the rostral portion. Abbreviations: an, angular; dt, dentary teeth; fo, frontal fossa; fp, frontal process; fr, frontal; hy, hyoid; ju, jugal; la, lacrimal; ld, left dentary; mt, maxillary teeth; n, nasal; pmt, premaxillary teeth; pr, premaxilla; qu, quadrate; rd, right dentary; rm, right maxilla; sr, scleral ring; su, surangular; te, teeth. Wang et al. (2022).

Bone tissue of the left tibiotarsus midshaft was sampled to determine the ontogenetic age of the holotype of Musivavis amabilis (MHGU-3000). A transverse section made through the sample exhibits two different kinds of the bone tissue: cortical bone and endosteal bone. The cortical bone is composed of a thicker (172–186 μm) layer of poorly vascularized bone resembling tissue, which has been considered as parallel-fibered bone in previously described Enantiornithines. A few secondary osteonal canals are present and may indicate an initial reconstruction of the primary bone. However, circumferential osteonal lamellae associated with the canals are rather poorly developed. No outer circumferential layer has been recognized in the sample of Musivavis amabilis, indicating that active bone deposition had not ceased at the time of death. 

Histology of the left tibiotarsus of the holotype (MHGU-3000) of Musivavis amabilis. Transverse section of the midshaft level is viewed in transmitted light. Note decreasing counts of osteocyte lacunae per area, for example from 18 in the innermost cortex to 11 in the outermost cortex (outlined areas in CB). The white arrows point an irregular interface between the cortical and endosteal bones, whereas the red arrows mark partially eroded osteocyte lacunae. Abbreviations: CB, cortical bone; eob, endosteal bone; ICL, inner circumferential layer; i-oslam, ill-developed osteonal lamellae; meca, medullary cavity; osla, osteocyte lacuna; pca, primary osteonal (neurovasular) canal; seca, secondary osteonal canal. Wang et al. (2022).

The endosteal bone forms the compact avascular inner circumferential layer, enclosing a large hollowed medullary cavity. The endosteal bone is variably thick (minimum: 30 μm; maximum: 47 μm) and accounts for at least a fifth of the total cortex. The cortical and endosteal bones are separated by a scalloping line visible on the section. This line represents the erosional front. Its irregular shape corresponds to variable rates at which the primary bone was resorbed, and provides evidence about the removal of earliest bone formed in the specimen. Based upon this, Wang et al. conclude that Musivavis amabilis (MHGU-3000) perished as a subadult near the ontogenetic stage characterized by the first growth deceleration.

A phylogenetic analysis found that Musivavis amabilis  is nested within a lineage that, in turn, is the sister taxon of the node including Bohaiornithidae and Pengornithidae. The analysis supports the monophyly of Longipterygidae, Pengornithidae, and Avisauridae. Musivavis was found as more closely related to Dunhuangia and Longusunguis than to other Enantiornithines, in a lineage that also includes Houornis and, tentatively, Yungavolucris (although the status of this taxon is far from clear, and it might instead be an Avisaurid). 

Reduced strict consensus of the shortest trees found by the unweighted analysis after pruning of the 'wildcard' taxa. Letters at branches indicate the alternative placements of the 'wildcard' taxa. Wang et al. (2022).

The osteology of Musivavis amabilis suggests that it was older than many other known juvenile Enantiornithines known, but still a subadult at the time of its death. It shows a unique set of features, which clearly support its establishment as a new species. Many of its features appear to support its inclusion within the Bohaiornithidae, but others run contrary to this, and a phylogenetic analysis found it was nested within a clade of 'Bohaiornithid-like' Birds outside the core Bohaiornithids. 

See also...

Online courses in Palaeontology. 

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Sunday, 27 March 2022

Hiker believed to have been killed by Bear in Montana.

A hiker is believed to have died in a Brown Bear, Ursus arctos horribilis, attack in the Absaroka Mountains of Montana on Thursday 24 March 2022. Craig Clouatre, 40, of Livingston in Park County, Montana, went missing while hiking with a friend Paradise Valley. A search carried out by officers from the Park County Search and Rescue Team, went on late into the night, but was unable to find him. The following morning a set of Human remains were discovered, showing what appeared to be signs of a Bear attack. These were subsequently identified as Mr Clouatre.

Craig Clouatre, 40, of Livingston, Montana, believed to have died in a Bear attack in Paradise Valley on Thursday 24 March 2022. Craig Clouatre/Facebook.

Brown Bears are highly adaptable large omnivores found across much of the Northern Hemisphere. They are extremely flexible in their dietary habits, and able to change their diet in response to Human or other environmental pressures in ways that few other large animals can manage. Whilst Bears have a fearsome reputation, and are rightly treated with great respect by people that share their environment, attacks on humans are exceptionally rare. 

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Communities evacuated following eruptions on Mount Taal, Luzon Island.

About 1100 people have been evacuated from five communities around Lake Taal on Luzon Island, the Philippines, following an eruption on Mount Taal, an 311 m high volcano forming an island in the middle of the lake on Saturday 26 March 2022. Activity on the volcano began slightly after 7.20 am local time, with a series of phreatic explosions (explosions caused by hot magma or lava coming into contact with water), which produced a column of ash and steam about 1.5 km high, as well as a rain of hot mud and strong smell of sulphur dioxide which affected local communities. The Philippine Institute of Volcanology and Seismologyhas raised the alert level of the volcano following the eruption, and begun evacuations of communities around Lake Taal. 

A volcanic column above Mount Taal, Philippines, following an eruption on 26 March 2022. CNN.

While the volcano is in itself dangerous, much of the concern is that Earthquakes or eruptions around it could trigger a landslide into the lake, triggering a tsunami wave. Tsunamis occur when large volumes of water are displaced by geological events, such as landslips or Earthquakes, forming waves which spread out through the surrounding water. Like other waves, tsunamis are not necessarily obvious in deep, open waters, but when they reach shallow or enclosed waterways can be extremely dangerous. This is because a tsunami isn't just a wave above the normal water-level, it is pressure wave beneath the surface, which is amplified in the enclosed space. A tsunami reaching the shore is typically preceded and followed by rapidly shallowing water. Thus people in areas prone to tsunamis know to evacuate the coast rapidly if the tide apparently goes out rapidly, since this is likely to be followed by the tide coming in rapidly. This gives us the English term 'tidal wave' which is no longer used, since it is inaccurate; the tides are caused by the gravity of the sun and moon, tsunamis are nothing to do with the tide. The term 'tsunami' comes from Japan, where earthquakes, and therefore tsunamis, are common.

How a landslip can trigger a tsunami. University of California, Santa Cruz/BBC.

The geology of the Philippines is complex, with the majority of the islands located on the east of the Sunda Plate. To the east of this lies the Philippine Sea plate, which is being subducted beneath the Sunda Plate (a breakaway part of the Eurasian Plate); further east, in the Mariana Islands, the Pacific Plate is being subducted beneath the Philippine Sea Plate. This is not a smooth process, and the rocks of the tectonic plates frequently stick together before eventually being broken apart by the rising pressure, leading to Earthquakes in the process. Material from the subducting Philippine Plate is heated by the temperature of the Earth's interior, causing lighter minerals to melt and the resultant magma to rise through the overlying Sunda Plate, fuelling the volcanoes of the Philippines.

Subduction beneath the Philippines. Yves Descatoire/Singapore Earth Observatory.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Dwarf planet 136472 Makemake reaches oposition.

The dwarf planet 136472 Makemake will reach opposition (i.e. be directly opposite the Sun seen from Earth) on Monday 28 March 2022 at 9.50 pm GMT. This means that it will both be at its closest to the Earth this year, about 51.75 AU (51.75 times the average distance between the Earth and the Sun, or about 7 714 890 000 km), and completely illuminated by the Sun. While it is not visible to the naked eye observer, the planets have phases just like those of the Moon; being further from the Sun than the Earth, 136472 Makemake is 'full' when directly opposite the Sun. The planet will be in the constellation of Coma Berenices and at its highest point in the sky at about midnight local time from anywhere on Earth (this is because the rising and setting of objects in the sky is caused by the Earth's rotation, not the movement of the object). (Even at it's very brightest 136472 Makemake will only have a Magnitude of 17.2, making it almost impossible to see with any but the largest of Earth-based telescopes, and where resolvable it will only be possible to see it as a point of light indistinguishable from a faint star.


The orbit and position of 136472 Makemake (2005 FY9) at 10.00 pm on Monday 28 March 2022. JPL Small Body Database Browser.

136472 Makemake orbits the Sun on an eccentric orbit tilted at an angle of 29.0° to the plane of the Solar System, which takes it from 37.8 AU from the Sun (37.8 times the average distance at which the Earth orbits the Sun) to 52.8 AU from the Sun (52.8 times the average distance at which the Earth orbits the Sun. With an average distance of 45.3 AU, 136472 Makemake completes one orbit around the Sun every 305 years. This means that the planet is almost stationary compared to the faster moving Earth, so that it reaches Opposition only two days earlier each year than the year before, and reaches Solar Conjunction (when it is directly on the opposite side of the Sun to the Earth), roughly six months later.

Hubble Space Telescope image of 136472 Makemake. Mike Brown/NASA.

136472 Makemake was discovered on 31 Match 2005 by a team led by Mike Brown of the Palomar Observatory in California. With a diameter of 1430 km it is considered to be the fourth largest dwarf planet in the Solar System (after 134340 Pluto, 136199 Eris, and 136108 Haumea) as well as the twenty second largest body in the Solar System, excluding the Sun (several moons, including our own, are larger). Makemake is also the second-brightest Kuiper belt object, after Pluto.

The surface of 136472 Makemake appears reddish at visual wavelengths, and spectral analysis suggests that it's surface is covered primarily by methane ice, with large amounts of ethane and tholins as well as smaller amounts of ethylene, acetylene and high-mass alkanes. Notably, nitrogen, although present, is observed at much lower levels than on Pluto and Triton, where it is the most abundant ice. 136472 Makemake apparently lacks any form of atmosphere, although it does have a satellite, S/2015 (136472) 1, which is estimated to be 175 km in diameter and orbits at a distance of at least 25 000 km, with an orbital period of at least 12 days.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter

Conraua kamancamarai: A new species of Slippery Frog from the Fouta Djallon Highlands of west-central Guinea.

The Fouta Djallon Highlands of west-central Guinea form a series of plateaus, deep valleys, and steep slope-faces covered by a mixture of tropical and sub-tropical forests and grasslands. The area receives some of the highest rainfall in West Africa, but also has a wide range of micro-climates, providing a highly diverse environment with a high number of endemic species, which is relatively understudied by scientists. The floral uniqueness of the region has long been recognised, and there have been many calls to protect areas of pristine forest being encroached upon by agriculture and Cattle ranching, but the faunal uniqueness of the area has been very little studied.

In a paper published in the journal Zoosystematics and Evolution on 19 January 2022, Karla Neira-Salamea of the Museum für Naturkunde Berlin, Joseph Doumbia of ONG EnviSud Guinée, Annika Hillers of the Wild Chimpanzee Foundation, Laura Sandberger-Loua, also of the Museum für Naturkunde Berlin, N’Goran Kouamé of the Laboratoire de Biodiversité et Ecologie Tropicale at the Université Jean Lorougnon Guédé, Christian Brede of Lübeck in Germany, Marvin Schäfer, again of the Museum für Naturkunde Berlin, David Blackburn of the Department of Natural History at the Florida Museum of Natural History, and Michael Barej and Mark-Oliver Rödel, once again of the Museum für Naturkunde Berlin, describe a new species of Slippery Frog from the Fouta Djallon Highlands of west-central Guinea.

Hörè Binti landscape, Fouta Djallon, Guinea. Neira-Salamea et al. (2022).

Slippery Frogs, Conraua spp., are endemic to Africa, with seven species currently recognised, one from East Africa, three from Central Africa, and three from West Africa. However, a recent phylogenetic study of one of these species, Conraua alleni, should in fact be considered to be a species cluster (group of morphologically identical but genetically distinct species, known as 'cryptic species') rather than a distinct species. With this in mind, Neira-Salamea et al. carried out morphological and genetic tests on a group of Slippery Frogs held in the Museum für Naturkunde Berlin, which were collected during an expedition to the Fouta Djallon in 2011, establishing that Frogs from Hörè Binti, Pita and Chute de Ditinn and Dalaba in the Fouta Djallon are all members of a new, previously undescribed species.

The new species is named Conraua kamancamarai, in honour of the late Kaman Camara, a long term field assistant and friend of the team, who began working with Mark-Oliver Rödel in 2002 on a survey to the Simandou Range that was organised by Conservation International, and worked with the team full time from 2007 until his death after a short illness in 2020, investigating the amphibians of the Nimba Mountains and other Guinean areas. Neira-Salamea et al. note that 'Kaman had outstanding skills in detecting and catching Frogs, and, more importantly, an unswerving positive attitude'. Kaman was born and lived in a remote village at the western foothills of the Simandou Range. He never received any formal education. Still, he repeatedly rejected other better paying job offers from mining companies, preferring instead to work with his frog team whenever it was possible.

Kaman Camara in June 2007 on Mount Nimba, Guinea. Inset figure taken on a Rapid Assessment to south-eastern Guinea, organised by Conservation International and Kaman’s first experience with frog work, from left to right: Mark-Oliver Rödel, Mohamed Alhassane Bangoura and Kaman Camara. Neira-Salamea et al. (2022).

Specimens of Conraua kamancamarai have a slightly dorsoventrally flattened, short and rounded body; the snout is rounded in dorsal and lateral view, the upper lip slightly projects forward. They range from 74.3 to 81.7 mm in length. Dorsal colouration ranges from uniform dark brown to predominantly brown with dark mottling or predominantly brown with dark spots. Ventral colour pattern of all specimens similar: whitish with distinct brown blotches, however, these blotches are lighter in the subadult specimens.

Colouration of life Conraua kamancamarai from the Fouta Djallon and surrounding region, Guinea, illustrating variation in colour pattern and skin texture. (a) From Dubreka, River Bindinbandan; (b) From Dalaba, Chute de Ditinn; (c) From Hörè Binti; (d) From Dubreka, River Bindinbandan; (e) From Dalaba, Chute de Ditinn; (f) From Télimélé, locality Kourakoto, river Didounpouriguè; Frogs in lower row in typical calling position, sitting in shallow water; specimens either not collected or not assignable to a voucher specimen, whereas the Frogs from Hörè Binti and Chute de Ditinn can be assigned to Conraua kamancamarai without doubt; the other Frogs may represent an undescribed Conraua species. Neira-Salamea et al. (2022).

Conraua kamancamarai occupies fast-flowing rocky streams with waterfalls within riverine forest in mountainous areas in the Fouta Djallon. Like other Frogs of the genus, Conraua kamancamarai is predominately nocturnal and aquatic. Despite their occurrence in fast flowing streams, adults show a preference for calmer river sections, where turbulent water is absent. Usually, Frogs are encountered at least partly submerged in shallow water, facing the riverbanks. When outside of the water, they remain within jumping distance to water. Disturbed Frogs seek shelter on the ground of pools, sometimes trying to burrow deeper into them and cover themselves with gravel or substrate. Mating has never been observed; however, single observations of clutches and jelly remnants of spawn indicate that oviposition sites are small puddles or depressions on the riverbanks near the spray water zone of cascades and waterfalls. Conraua Tadpoles usually were observed in silted calm ponds where up to 50 Tadpoles of about the same size have been encountered.

The type locality of Conraua kamancamarai near Konkouré Fetto, Fouta Djallon, Guinea. The Frogs live in clear, fast flowing streams, with riverine forest. Neira-Salamea et al. (2022).

The forest fragments where Conraua kamancamarai occurs are generally degraded by anthropogenic disturbance, particularly Peanut and Rice crops and Cattle grazing. The type locality is located between Konkouré and the largest city within the Fouta Djallon, Mamou, within a relatively short distance to the connection road and was surveyed on 20 June 2011. Along the national route one (N1), one of the largest roads connecting the East with the West of Guinea, houses are numerous, but already within a relatively short distance to the road, Human presence may be considerably scarcer. Slopes are either covered by an open, short, dry forest with signs of Cattle grazing and used for charcoal production or comparatively large fields for Peanuts or Rice crops. Only steep slopes surrounding rivers had sometimes larger trees and denser vegetation with higher humidity levels than the surroundings. The type locality is at a river within denser forest, with large boulders and some cascades, allowing for a diverse river site with fast and slow flowing parts and comparatively clear water. These forests are not protected and were in the past burned by the population as protest against government decisions in Conakry.

The surroundings of the type locality are heavily degraded by agriculture, Cattle grazing and charcoal production (inset figure). Neira-Salamea et al. (2022).

The classified forest (partly protected areas allowing forestry) of Hörè Binti is located within a mountainous area containing several freshwater sources. It was surveyed from 22–23 July 2010. Many fast-flowing streams with cascades have its source on the mountain. The habitat degradation due to anthropogenic alterations was dramatic and only very small forest fragments remained. The anthropogenic pressure consisted of cultivations/fields (mainly Peanut and Rice) and grazing Cattle. Only streams were surrounded by some remaining larger trees. The Ditinn/Dalaba site was within a small fragment of gallery forest with a stream, next to the waterfall of Ditinn. It was surveyed from 24–25 July 2010. Although there is a small village next to the forest, only minor anthropogenic alterations were detectable.

Because the full range of Conraua kamancamarai is unknown, Neira-Salamea et al. recoment that it be treated as 'Data Deficient' under the terms of the International Union for the Conservation of Nature’s Red List of Threatened Species. However, they also note that if the known populations do represent the entire range of the species, then it should be considered to be Endangered.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter

Wednesday, 23 March 2022

Italian tourist dies after being bitten by a Shark in the Caribbean.

An Italian tourist has died after being bitten by a Shark while snorkelling of a beach on San Andres Island on the Caribbean coast of Colombia on Friday 18 March 2022. Antonio Straccialini, 56, from the Abruzzo Region of Italy was received a single bite to the thigh, and while he was able to pull himself out of the water, he died of blood-loss shortly after. The identity of the Shark is not completely certain, but there are reports of a pair of Tiger Sharks, Galeocerdo cuvier, being seen in the area before the attack, and this species is known to occasionally attack Humans.

A Tiger Shark in the Bahamas in 2012. Albert Kok/Wikimedia Commons.

Despite their fearsome reputation, attacks by Sharks are relatively rare and most attacks on Humans by Sharks are thought to be mistakes. Tiger Sharks have a diverse diet, including invertebrates, Fish, Birds, Marine Reptiles and Marine Mammals, which we superficially resemble when we enter the water. Marine Mammals are attacked principally for their thick adipose (fat) layers, which are a nutritious high-energy food, but which we lack. Due to this, when Sharks do attack Humans, these attacks are often broken off without the victim being consumed. Such attacks frequently result in severe injuries, but are seldom immediately fatal, and victims are likely to survive if they receive immediate medical attention.

The location of San Andreas Island. Google Maps.

Following the incident there are reports of local people organising a Shark hunt to find and kill the offending Animal, despite the fact that this is illegal in Colombia, where Sharks are protected, as well as pictures having been posted on social media of hunters with a dead Nurse Shark, Ginglymostoma cirratum, a species considered to present no threat to Humans. This has been condemned by environmental groups in Colombia, and in particular Colombian actor and dive master Victor Mallarino, who has observed that this response is completely inappropriate, and a consequence of poor public education about Sharks in the country. In Italy, meanwhile, many people are questioning why no alarm was raised after a Shark of a species considered to be dangerous was seen in the viacinity of Human bathers.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter